A few things to point out, before you crank up Visual Studio. This is only open to UK residents, and you need to register with the promotion (at www.my-rewards.com) before you start submitting the apps to the Marketplace. Also, there is a quality threshold, and you only earn one of the 1400 available point for your application once Microsoft has agreed that the app is unique and original. From the terms and conditions:
If a user submits a unique and original application that is accepted and published by Windows Phone Marketplace, they will be awarded a point for application submission as detailed above. Unique and Original would mean that your application must be different from an application you or any other party may have created before which is beyond aesthetic variables such as colour, font or other superficial factors etc. of the application.
There is also a bonus prize draw available to all who enter the promotion. All you need to do is register on AppHub (which will still cost you the usual membership fee).
Unlike a direct developer competition, I like this idea. It's optional on the developer, but those that enter all have something of value they can take away from the contest. Assuming that all the points are allocated, that's 1400 new applications in the Windows Marketplace from the UK region.
Throw in a normal statistical spread and MSDN UK have every chance of picking up 75 to 100 really high quality applications and maybe four or five outright wonderful stand-out titles. And it's unlikely that the developers would stop once they reach the maximum allocation of four points - possibly 150 new developers to stay in the Windows Phone ecosystem, and another 200 with solid skills in their toolbox?
We'll watch carefully to see how successful the Windows Phone Developer Program is in the UK, and if the model will move into other territories!